Prediction of profitability of topworking in older apple orchards under contemporary economic conditions of the Czech Republic

: In the Czech Republic, there is still a predominance of obsolete apple orchards that were established more than 15 years ago and that are not profitable under contemporary conditions. Typical features of these orchards are low or medium tree densities, freely growing semi-standard trees or hedgerows on semi-dwarf, or sometimes also on vigorous, rootstocks. The farmers are not always in a position to completely renovate them, and therefore they are interested in their topworking. The present paper studied the effectiveness of this measure under the current economic and market conditions of this country, using 3 types of orchards with different spacings and rootstocks and 5 groups of tree densities. Four cultivars were chosen as examples of different starting statuses for the modelling of subsequent development in three time horizons and for the prediction of profitability of this treatment. The profitability is based on an increase in farmer prices for cultivars that are presently recommended for replacement of the older ones according to the recent development of these prices on the fresh market. In the case of topworking for Spartan cv., an economic return of the measure can be expected at the earliest after 8 years of running the treated orchard. The greatest increase in profit can be achieved in orchards on the rootstock M 9. Nevertheless, with the decline of tree numbers in the orchard, or with the increase in tree losses, the general economic effectiveness of topworking notably falls. In the case of trees on the rootstock MM 106, this measure can have an economic effect only if at least 80% of the trees is in a good health state and it is presumed that the orchard will be used for another 10 years at least. A list of recommended cultivars to be used for replacement of the old ones is given.